Objectives: In our study, we present the first complete genome sequence of an HCV subtype 1g isolate. Hepatitis C virus isolates have been classified into six main genotypes and a variable number of subtypes within each genotype, mainly based on phylogenetic analysis. Although the most reliable analyses of genetic relationships among genotypes and subtypes are performed using complete genome sequences (or at least the full coding region), up to now only 31 out of 80 confirmed or proposed subtypes have at least one complete genome available.

Methods: Virus genome was isolated from a serum belonging to a Spanish woman that received a blood transfusion in 1996. Serum was obtained before pegylated interferon plus ribavirin treatment to which the patient didn't respond. Complete HCV-1g genome was obtained by direct sequencing of ten overlapping RT-PCR fragments. ClustalW implemented in MEGA was used to obtain a multiple alignment. All phylogenetic trees were constructed by maximum likelihood in PHYML with the nucleotide substitution model that best fit the data for which we used the procedure implemented in Modeltest. The robustness of the tree topology was assessed by bootstrap analysis with 1000 replicates implemented in PHYML.

Results: The nucleotide sequence of the HCV-1g genome (9490 nt) includes the complete coding region and partial sequences from both 5'UTR and 3'UTR. Phylogenetic and genetic distance analyses reveal that HCV-1g is the most divergent subtype among the HCV-1 confirmed subtypes. HCV-1g genome does not arise as a recombinant form of previous known genotypes or subtypes.

Conclusion: In light of this, we propose to change from provisional to confirmed the current status of its subtype-specific designation.

Session Details

Date:

19/04/2008

Time:

00:00-00:00

Session name:

18th European Congress of Clinical Microbiology and Infectious Diseases